The new energy facility will add value to the organic fraction of urban solid waste combined with wastewater treatment sludge, transforming them into new high-value products such as biopolymers, biofertilizers, and green graphene. ICLEI Europe will explore how other cities can replicate the technologies and processes developed by the project.

The Spanish city of Zaragoza has officially launched its new flagship biorefinery, developed under the CIRCULAR BIOCARBON project, funded by the Bio-Based Industries Joint Undertaking under the European Union's Horizon 2020 program. Managed by Urbaser, in collaboration with the Zaragoza City Council, the biorefinery will convert urban organic waste and wastewater treatment sludge into high-value products such as biopolymers, biofertilizers, and green graphene.

The inauguration event at the Zaragoza Urban Waste Treatment Center and the Alfonso Maíllo Innovation Center brought together key European stakeholders, and leaders from industry, politics, and academia, to witness the facilities’ cutting-edge innovations.

Natalia Chueca, Mayor of Zaragoza, emphasised the city’s role as leader in circular economy, saying: "Once again, Zaragoza is becoming a leader in the circular economy. I am deeply grateful to Urbaser and all the companies involved in this project, which will undoubtedly become a model for Spain and Europe. Zaragoza once again demonstrates that by betting on the green economy, we create jobs and wealth while taking giant steps toward shaping sustainable and healthy cities. Zaragoza is already a leader in sustainable mobility, urban greening projects like the Zaragozan Forest and the Huerva River, and in the circular economy, exceeding the national recycling rate. Now, we are also a reference in new technologies aimed at transforming waste."

The biorefinery not only advances traditional waste treatment processes, but also provides environmental and economic benefits to Zaragoza and the surrounding regions by reducing landfill waste. The facility will enable the production of various bio-based materials and products, supporting local industries in adopting sustainable practices.

"The launch of the biorefinery in Zaragoza is a significant milestone for CIRCULAR BIOCARBON and Urbaser, contributing to a more circular bioeconomy," said Fernando Abril-Martorell, CEO of Urbaser. He explained that "the new facility operates with a circular model where innovation takes center stage, shifting from waste and wastewater management to material production, thereby supporting industries in their biotechnology-driven transition. The process will also aid the production of marketable final products, reducing industries' reliance on non-renewable resources."

The CIRCULAR BIOCARBON biorefinery is a unique model, with process lines implemented in two different locations (Zaragoza, Spain, and Sesto San Giovanni, Italy) for logistical, customer, and market reasons. This multi-site approach will test the biorefinery's performance across different waste management systems, ecosystems, and existing industrial practices, boosting its potential for replication across Europe. CIRCULAR BIOCARBON has a budget of €23 million develop this project, and consists of 11 entities coordinated by Urbaser.

For his part, Nicoló Giacomuzzi, Executive Director of Bio-Based Industries Joint Undertaking, emphasized that the opening of this revolutionary facility is an important milestone in the field of the circular economy. “Not only will it turn waste into high-value bioproducts and set a new European standard for circularity, but it will also create local jobs, promote sustainable growth, and save resources in the region. This is why the organisation proudly supports this pioneering industrial project, as it will boost competitiveness and drive sustainable industries in Spain and Europe.”

CIRCULAR BIOCARBON has established the City Interest Group to help cities and local authorities replicate and get a better understanding of the project’s work. In this context, ICLEI will organise a webinar on 4 December that will explore the potential of transforming biowaste into valuable bio-based materials, moving beyond more mainstream energy applications, and with a particular focus on urban and regional bioeconomies. The webinar will also present local economic development policies, such as bioeconomy clusters and industrial symbiosis, that create a supportive environment for the development and uptake of bio-based materials. Interested participants can register here.